294 



THE PEANUT— THE UNPREDICTABLE LEGUME 



probably due to the rosette virus (158). Typical mosaic conditions have 

 been described from Africa (56) and the East Indies (175) as rosette, 

 and yet mosaic has been reported by observers unwilling to regard it as 

 a phase of rosette. In spite of this confusion, however, certain tentative 

 conclusions may be reached, largely as a result of opinions expressed. 



ROSETTE 



Importance. Several reports include statements which may be used 

 in evaluating the importance of the virus disease called "rosette." This 

 information is condensed in table 5. 



Table 5. — Estimates of Importance of Rosette 



Description. Rosette is characterized by a "condensation" of the 

 plant. Petioles and internodes are shortened, giving the plant a typical 

 rosette or clumped appearance. Storey and Bottomley in 1928 (144) 

 gave a detailed description of peanut rosette as it was then recognized, 

 and the following description is condensed from their report: 



The whole plant is severely stunted. Leaves, especially the 

 younger ones, are more or less definitely chlorotic and faintly mottled. 

 New leaves are pale yellow with dark green veins. Successive leaves 

 are smaller, curled and distorted, uniformly yellow, and without 

 green veins. These leaves usually turn green and eventually appear 

 almost normal. Yield depends upon time of infection. If infection is 

 early, small, sessil flowers which do not open may be formed, but 

 they do not mature into fruits. If plants are infected after seeds begin 

 forming low yields may be obtained. The disease is transmitted by 

 grafting, is not seed-borne, or soil-borne. 



An earlier observation indicated a general deterioration of infected 



